Add text to an image and store - Flutter - image

Question

Good day ,I am generating certificates and for this I have a template where I must write user data, for the moment I am creating the certificates in pdf format, but the ideal would be to use images or convert those pdf to image since it is easier for the user to handle images, I have not found any library capable of writing in images that works correctly.
At the moment I am trying to use Image. https://pub.dev/packages/image.
I have the following code, but it fails to add a text fragment in the image.
imagecert = await ManagerDB().getcertificate(certificatetemplate); //imagecert is uint8list
if (imagecert != null) {
mg.Image ima = mg.Image.fromBytes(300, 200, List.from(imagecert)); Image works with list<int>
mg.Image imag = mg.drawString(ima, mg.arial_14, 0, 0, 'Hello World'); //here the code does not work
List<int> data = mg.encodePng(imag);
Uint8List bytes = Uint8List.fromList(data);
setState(() {});
return bytes;
} else {
print("Enlace no encontrado");
}
I don't know if there is a simpler solution to write text in an image. It is required to store those images.
Thank you

Answer 1

you can put image inside widget and add to that widget text
and converted to image using globalKey (don't forget to pass globalKey to key of that sepecific widget )
Future<Uint8List> _convertWidgetToImage(GlobalKey globalKey) async {
RenderRepaintBoundary boundary =
globalKey.currentContext!.findRenderObject() as RenderRepaintBoundary;
ui.Image image = await boundary.toImage();
ByteData byteData =
(await (image.toByteData(format: ui.ImageByteFormat.png)))!;
Uint8List pngBytes = byteData.buffer.asUint8List();
return pngBytes;
}